1. Field of the Invention
The invention generally relates to a flash memory apparatus, and more particularly, to a method for managing the damaged-column address information of a flash memory.
2. Description of Related Art
With the advances in electronic technology, electronic devices have become an essential tool in people's lives. In order to provide a huge data storage space in an electronic device, the flash memory has played a major role for the field of the storage apparatuses in today's electronic devices.
In a flash memory, some of the memory cells for column addresses have failed to normally perform read/write operations even at the factory's shipping stage. The information of these damaged-column addresses are, in predetermination, stored in a damaged-column manager in a memory controller which the flash memory belongs to. The memory controller then selects some appropriate memory cells for reserved column addresses in the flash memory so as to replace the memory cells with damaged-column addresses. However, in the prior art, the damaged-column address information stored in the damaged-column manager is obtained through a testing on the flash memory before shipping out the good from the factory, which means the damaged-column address information obtained against a single flash memory is fixed and unchanged. Once the flash memory generates a new damaged-column during the use, the above-mentioned damaged-column manager is unable to know these newly-occurred damaged-column addresses. In other words, the damaged-column manager is unable to prevent the accessing operation on the newly-occurred damaged-columns which may make the data lost.